A variety of field cookers are known. The cookers generally include some form of outer housing, a cooking container which is received in the housing, a cover for the cooking container and means for containing a heat source, generally under or along side of the food container.
Although the word portable is used in conjunction with many known cookers, the cookers are portable only in the sense that they may be carried from one location to another intermediate their use as a food warming container. Known portable field cookers are not practical for heating or cooking food while on the move and the known units are certainly not acceptable as portable cooking units for use while being carried by a backpack or hiker while the carrier is on the move and the cooker is warming the food carried therein.
As food in a cooker is heated, it will tend to expand. Although a number of cookers are known which include pressure relief valves to allow the escape of gases from the interior of the cooking vessel, such structure is depend upon the cooker being in an upright, stationary condition. If the cooker is being transported, particularly by a person on foot, a certain amount of agitation will occur and it is likely that not only will gas escape from the interior of the vessel, but that the contents of the vessel will escape. Known cookers do not provide any means for retaining escaped contents of the vessel when the cooker is being transported.
Known portable field cookers, if transported, particularly by a person on foot, would pose a significant danger to the carrier and to the environment through which the cooker is carried if a fuel supply is burning therein. Known field cookers rely on liquid or solid fuel for heating the contents thereof and, particularly in the case of liquid fuel, carrying such a cooker when the fuel is ignited could be quite dangerous. In the case of solid fuel, the fuel is likely to create embers and sparks, which would exit the cooker and create potential fire hazard to the environment.